Dental implant that increases bone support

ABSTRACT

This describes an implant design that increases the amount of bone around the implant by increasing its length in order to place a longer implant without the need for a sinus elevation surgery in the posterior maxillary region where bone stock is not sufficient by employing the principles of displacement procedures in implantology which rely on regeneration of patient&#39;s own bone and have been used for years in the dentistry for orthodontic procedures. The implant system we have designed has a pressure adaptor ( 4 ) that protrudes and advances through the apical part of the implant. Pressure adaptor ( 4 ) is advanced within the bone until desired length of implant and bone is achieved. This procedure forms significant amount of bone around the implant within the floor of maxillary sinus. Floor of maxillary sinus is elevated. New bone is formed without the need for an additional surgery. This implant system can also be used for distraction osteogenesis in sinus floor or other anatomic spaces by a unique application different from distractor implants.

Dental implants are biocompatible functional devices that are placedinto bones for substituting an extracted tooth or providing support tofixed or mobile prostheses. The goal of implant design is to providesufficient initial stability and accomplish osteointegration as early aspossible after implantation. Implants are kept load-free for 3 to 6months following primary surgery. During this period, new regular bonethat will stand against the occlusive loads is formed around the implant(osteointegration); so the implant becomes stable enough to resistfunctional forces created during mastication. Following this stage,prosthetic restoration is done onto the implant to obtain a functionalimplant.

Magnitude of mechanical stress on alveolar bone depends on the diameterand length of the implant; proper placement of implants with respect tothe direction of the forces applied; the number of implants anddistribution of the forces. Increasing length of the implant increasesits load-bearing surface. Increased length is also crucial for primarystability. Implant should resist shearing and torque forces whenabutment is mounted. Increased length also reduces the stress applied onthe neck of the implant. Implant body design, screw geometry and surfacecharacteristics are continuously being improved to strengthen theimplant-tissue interface, and to attain ideal load transfer; eventuallyto increase the success and survival of the implant.

High number of anatomic spaces and important nerves in the oral regionlimits the length of the implants to be used and mandates a detailedexamination. If occlusive forces are increased, larger and longerimplants should be used. However, confined width and length of the bonerestricts the use of implants with appropriate length and width. Thisnegatively affects the long-term success of the implant.

Sagging of the sinus floor, insufficient height and quality of bone arecommon problems in the patients that have remained toothless for a longtime particularly in the posterior maxillary region, and it is rarelypossible to place an implant of sufficient length in proper position.Even if the implant can be placed, this situation causes the implant tohave bone support with poor quality. We have inspired from thedisplacement technique that is based on regeneration of the patient'sown bone and widely used in the dentistry for orthodontic procedures toplace a long implant to the maxillary posterior region without the needfor sinus lifting where bone distance is particularly insufficient; andby using this technique in implantology we aimed to increase the amountof bone around the implant by increasing its length.

Throughout the normal development of the root of the teeth, increasedroot length is associated with increased length of alveolar bone. Thisphysiologic and remarkably slow mechanism allows growth of roots tosufficient length without jeopardizing important structures such asmaxillary sinus or inferior alveolar nerve. In a similar manner, theimplant we have designed can be gradually lengthened to allow the use ofan implant of sufficient length in areas with insufficient bone length.

The implant system we have designed consists of 5 parts (FIG. 1, 2, 3,4, 5). In the implant system, there is a pressure adaptor (4) thatprotrudes and advances through the apical part of the implant body (1).Following insertion of implant system into the posterior maxillary areaand attainment of osteointegration (FIG. 6), driving screw (2) is usedto force the pressure adaptor (4) of the implant system into the floorof the sinus (FIG. 7). Force applied within physiologic limits initiatesremodeling around the terminal part of the pressure adaptor (4) similarto the behavior of the bones of the teeth that are exposed toorthodontic forces. This process is carried on until a desired implantand bone length is achieved. Implant system also contains a leak-proofelement (5) that prevents leakage between pressure adaptor and theimplant body. A screw cap (3) is mounted on the implant body to preventimmigration of bacteria and foreign bodies from the oral cavity. Theseall lead to significant bone formation around the implant system withinthe maxillary sinus floor. Floor of maxillary sinus is elevated (FIG.7). New bone is formed without the need for an additional surgicalprocedure.

Our newly developed implant system provides new bone formation by boneremodeling (FIG. 6, 7). Unlike the implant distractors that make use ofdistraction osteogenesis by forming fracture on the bone and make use offlexible fracture callus to form new bone, this implant system make useof remodeling without creating a fracture. Bone formation throughremodeling is much slower. This implant system offers a higher patientacceptance as it requires no additional surgery and is less traumaticcompared to distractors.

However, by unique application different from the other distractors,this implant system can also be used for distraction osteogenesis inmaxillary sinus or other anatomic spaces (FIG. 8, 9). Unlike otherdistractor implants which require osteotomy at the middle part of theimplant, in this system only a minimal fracture is formed at thecortical bone above the apical part of the implant as presented in FIG.8 to form callus and consequently new bone in a way similar todistraction osteogenesis. For this procedure, driving screw (2) isadvanced and pressure adaptor (4) forces fractured part through theanatomic space fairly faster compared to remodeling (FIG. 9). In thedistractor implants osteotomy line is at the middle part of the implant.

1. This device is a dental implant used to form new bone and to increasethe bone support at the apex of the implant system when placed in thesinus floor or in other anatomic spaces or areas adjacent to anatomicspaces by making use of principles of remodeling and distractionosteogenesis; and it consists of implant body (1), pressure adaptor (4)that are in direct contact with the bone and driving screw (2), implantcap (3), and leak-proof element (5) that are not in direct contact withthe bone.
 2. Mentioned in claim 1 is a dental implant capable ofincreasing the bone support and characterized by new bone formationusing the remodeling principle without causing a fracture afterplacement, by exertion of propulsive forces apically through the apex ofthe implant body (1) via pressure adaptor (4) similar to rooting of theteeth.
 3. Mentioned in claim 1 is a dental implant that increases thebone support and is characterized by formation of a small fracture atthe cortical bone of the anatomic spaces that is equal to the apicaldiameter of the pressure adaptor (4) before placement and production ofa distraction callus at this area using principles of distractionosteogenesis by means of compression forces on the free fragment of boneexerted via the pressure adaptor (4) that moves the fragment towards theanatomic space.
 4. Mentioned in claim 1 is the implant body (1)characterized by its fixed position in the bone and it reside within theintact bone where no fracture is formed.
 5. Mentioned in claim 1 is theimplant body (1) characterized by its open end at the apical directionwhich allows pressure adaptor (4) to protrude from the implant body (1)and exert compression forces on the bone in the apical direction. 6.Mentioned in claim 1 is the pressure adaptor (4) characterized bystimulation of new bone formation by protruding through the apical endof the implant body (1) that has a fixed position in the bone andexertion of compression forces apically through the apical end of theimplant system.
 7. Mentioned in claim 1 is the driving screw (2)characterized by its design that propels the pressure adaptor (4)through the apical end of the implant body (1) without causing anyrotational movement.